Pressure indicating device for a tire

ABSTRACT

An apparatus mounted on a valve for indicating a tire pressure comprising a pressure indicator including a downward pipe having an inner thread, a hollow downward cylinder projected into pipe, cylinder having a bottom opening, a mainspring having one end coupled to cylinder, mainspring being capable of pivoting as air through opening, and a pointer coupled to the other end of mainspring. In a mounted state of pressure indicator and valve, inner thread of downward pipe is secured to valve and cylinder is urged against valve to form an air path from tire to mainspring through valve and opening for pivoting pointer

FIELD OF THE INVENTION

[0001] The present invention relates to tires of motor vehicle and more particularly to a pressure indicating device for tire of motor vehicle with improved characteristics

BACKGROUND OF THE INVENTION

[0002] A conventional valve 20 of a tube-less tire is projected from rim 10 as illustrated in FIGS. 1 and 2 Valve 20 comprises a hollow cylindrical member 30 through rim 10, a tube member 40 having a lower portion secured within bore of hollow cylindrical member 30 and an upper portion with outer threaded section 402 and an inner threaded section 401, a channel member 50 having a narrow inner hole: a spring 80; a cap 60 having an outer threaded section 601, and an elongate slender bar 70 having a thin disk 701 on lower part with spring 80 anchored between the narrow inner hole of channel member 50 and a top of the elongate slender bar 70. The elongate slender bar 70 is inserted through the channel member 50 and cap 60 until disk 701 is stopped by bottom end of the channel member 50 which is in turn secured in tube member 40. Also, threaded section 601 of cap 60 is secured to the inner threaded section 401 of tube member 40 In inflating tire, air is pumped into tire through bores of cap 60 and channel member 50 by pushing down the elongate slender bar 70 by needle (not shown) for disengaging disk 701 from bottom end of the channel member 50. In the mean time, a person can know the fullness of the tire by observing the pivoting of pointer of a pressure gauge coupled to an air pump. But in a use state of tire, above air passage is closed Further, person can only knock on the tire by hand or foot for generally determining a fullness thereof by feeling its hardness or hearing its sound prior to driving However, such technique is not reliable. Thus improvement still exists

SUMMARY OF THE INVENTION

[0003] It is therefore an object of the present invention to provide an apparatus mounted on a valve of a tire for indicating a pressure thereof The apparatus comprises a pressure indicator including a downward pipe having an inner thread, a hollow downward cylinder projected into the pipe, the cylinder having a bottom opening, a mainspring having one end coupled to the cylinder, the mainspring being capable of pivoting as air through the opening, a pointer coupled to the other end of the mainspring, and a scale In a mounted state of the pressure indicator and the valve, the inner thread of the downward pipe is secured to the valve and the cylinder is urged against the valve to form an air path from the tire to the mainspring through the valve and the opening for pivoting the pointer

[0004] It is another object of the present invention to provide an apparatus mounted on a valve of a tire for indicating a pressure thereof The apparatus comprises a pressure indicator including a cap having an inner thread secured to the valve, a hollow downward cylinder projected into the cap, the cylinder having a bottom opening, a spring put on the cylinder, a mainspring having one end coupled to the cylinder, the mainspring being capable of pivoting as air through the opening, a pointer coupled to the other end of the mainspring, and a scale In a mounted state of the pressure indicator and the valve, the valve is closed. While in a pressed state of the pressure indicator, the spring is compressed to urge the valve by the cylinder to form an air path from the tire to the mainspring through the valve and the opening for pivoting the pointer

[0005] The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0006]FIG. 1 is an exploded view of valve of tire according to prior art,

[0007]FIG. 2 is a cross-sectional view of the assembled valve of FIG. 1,

[0008]FIG. 3 is a perspective view of a first preferred embodiment of pressure indicating device for tire according to the invention, pressure indicating device being mountable on valve,

[0009]FIG. 4 is a cross-sectional view of assembled pressure indicating device and valve of FIG. 3 with a greatly enlarged fragmentary view on top showing the area in circle A;

[0010]FIG. 5 is a cross-sectional view of a second preferred embodiment of pressure indicating device for tire according to the invention where pressure indicating device is mounted on valve, and

[0011]FIG. 6 is a view similar to FIG. 5 where pressure indicating device is pressed to show pressure of tire.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Referring to FIGS. 3 and 4, there is shown a first preferred embodiment of pressure indicating device 3 constructed in accordance with the invention mountable on a valve 2 which is projected from rim 1 of tire of an automobile Valve 2 is a well known device and comprises, as stated above a hollow cylindrical member 21 through rim 10; a tube member 22 having a lower portion secured within bore of hollow cylindrical member 21 and an upper portion with outer threaded section and an inner threaded section, a channel member 23 having a narrow inner hole, a spring 26; a cap 24 having a top recess served as air inlet 27 and an outer threaded section, and an elongate slender bar 25 having a thin disk on lower part with spring 26 anchored between the narrow inner hole of channel member 23 and a top of the elongate slender bar 25 The elongate slender bar 25 is inserted through the channel member 23 and cap 24 until disk is stopped by bottom end of the channel member 23 which is in turn secured in tube member 22. Also, threaded section of cap 24 is secured to the inner threaded section of tube member 22.

[0013] The pressure indicating device 3 comprises a space 31 enclosed by a transparent glass on top and a disk member on bottom, a downward pipe extended from disk member having an inner thread, a hollow cylinder 32 projected from bottom into pipe, the cylinder 32 having an opening 322 on lower end, a mainspring 33 having one end coupled to the cylinder 32, the mainspring 33 being capable of pivoting as air through opening 322, a pointer 34 coupled to the other end of mainspring 33, and a graduated scale 37 on dial. In a mounted state of pressure indicating device 3 and valve 2, the inner thread of downward pipe is threadedly secured to outer threaded section of tube member 22 and bottom of cylinder 32 is urged against top of elongate slender bar 25 to press down the elongate slender bar 25 a predetermined distance. Hence, air is flowed from tire to mainspring 33 through valve 2, air inlet 27, and opening 322 As a result, pointer 34 is pivoted an angle proportioned to the pressure of air applied on mainspring 33. In brief, it is possible of knowing a pressure of tire by mounting pressure indicating device 3 on valve 2

[0014] Referring to FIGS. 5 and 6, there is shown a second preferred embodiment of pressure indicating device 3 constructed in accordance with the invention The difference between first and second preferred embodiments are detailed below. As the downward pipe is eliminated, the pressure indicating device 3 of second preferred embodiment further comprises a spring 36 put on cylinder 32 and a cap 35 having an inner thread so as to threadedly secure to outer threaded section of tube member 22. In a normal state (i.e., not in the state of inflating tire), pressure indicating device 3 is mounted on valve 2. Also, at this position, bottom of cylinder 32 is not urged against top of elongate slender bar 25. Hence, elongate slender bar 25 is not moved While in a case that for example, driver wants to know the pressure of tire the driver can press pressure indicating device 3 to compress spring 36 so as to urge top of elongate slender bar 25 by the cylinder 32. Hence, elongate slender bar 25 is pressed down a predetermined distance Accordingly, air is flowed from tire to mainspring 33 through valve 2, air inlet 27, and opening 322. Likewise, pointer 34 is pivoted an angle proportioned to the pressure of air applied on mainspring 33. In brief, it is possible of knowing a pressure of tire by pressing pressure indicating device 3 on valve 2.

[0015] While the invention has been described by means of specific embodiments numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims 

What is claimed is: 1 An apparatus mounted on a valve of a tire for indicating a pressure thereof the apparatus comprising a pressure indicator including a downward pipe having an inner thread, a hollow downward cylinder projected into the pipe, the cylinder having a bottom opening, a mainspring having one end coupled to the cylinder, the mainspring being capable of pivoting as air through the opening, a pointer coupled to the other end of the mainspring, and a scale wherein in a mounted state of the pressure indicator and the valve, the inner thread of the downward pipe is secured to the valve and the cylinder is urged against the valve to form an air path from the tire to the mainspring through the valve and the opening for pivoting the pointer 2 An apparatus mounted on a valve of a tire for indicating a pressure thereof the apparatus comprising a pressure indicator including a cap having an inner thread secured to the valve, a hollow downward cylinder projected into the cap the cylinder having a bottom opening, a spring put on the cylinder, a mainspring having one end coupled to the cylinder, the mainspring being capable of pivoting as air through the opening, a pointer coupled to the other end of the mainspring, and a scale wherein in a mounted state of the pressure indicator and the valve, the valve is closed, and in a pressed state of the pressure indicator, the spring is compressed to urge the valve by the cylinder to form an air path from the tire to the mainspring through the valve and the opening for pivoting the pointer 